With the rapid development of the liquid crystal display (LCD) industry, various types of new liquid crystal display products have been produced. Since an LCD panel is a non-self-luminous display panel, it can only exert its display function with the aid of a light source provided by a backlight module. Depending on the position of the light source in the backlight module, the backlight module can be either edge-lit or direct-lit, wherein in a direct-lit backlight module, the light source is disposed below the LCD panel so that the LCD panel can gain a high light source intensity. Therefore, LCD products of this type are generally used in displays with a high demand for brightness such as a computer screen and a liquid-crystal display television.
In current direct-lit backlight modules, as shown in FIG. 1, a plurality of luminous bodies 30 arranged in an array, for example, light-emitting diode (abbreviated as LED) devices, are fixed on a back plate 10, wherein a reflector sheet 20 laminated on the back plate 10 is provided with a plurality of apertures corresponding to the above LED devices, the shape and size of the apertures matching that of the LED devices; as such, the relative position of the reflector sheet 20 can be fixed by the LED devices passing through the above apertures.
However, in the backlight module with the above structure, the size of the apertures of the reflector sheet 20 is equivalent to that of the LED device; in this case, the prolonged heating of the LED device may lead to expansion of part of the reflector sheet 20 around the LED device, and the deformation stress caused by the expansion has nowhere to release, thereby causing the reflector sheet 20 to deform, resulting in uneven reflection of light.